Folded bass horn speaker

ABSTRACT

The specification discloses a folded bass horn speaker having a rectangular speaker cabinet with a rear wall and a front speaker opening. A housing having the exterior shape of a pyramid is mounted within the cabinet, with the pyramid base disposed toward the rear wall and the pyramid vertex disposed toward the front speaker opening. A speaker is mounted in the housing to direct sound through the pyramid base. A sound reflector having the shape of a pyramid is mounted at the base on the rear wall, with the reflector vertex being directed toward the speaker. Sound emitted from the speaker is reflected from the reflector and travels between the housing and the interior walls of the cabinet outwardly through the front speaker opening to provide a flat impedance curve and a smooth base response to to approximately 2,000 cycles per second.

United States Patent OTHER PUBLICATIONS John C. Goodell, LoudspeakerEnclosures, Radio & Television News, Nov. 1949.

Fox Oct. 14, 1975 [54] FOLDED BASS HORN SPEAKER Y PrimaryExaminer-William C. Cooper l [75p] Inventor Ronald E Dal as TexAssistant ExaminerTommy P. Chm Assigneel Showsollnd, Dallas, Attorney,Agent, or FirmRichards, Harris & '22 Filed: Jan. 30, 1974 Medkck [21]Appl. No.: 437,888 57 ABSTRACT The specification discloses a folded basshorn speaker [52] U5. Cl. 179/1 E; 181/155 having a ct g speaker cabineti h a r wall '[51] Int. Cl. H04R 1/28 and a front speaker opening. Ahousing having the ex- [58] Field of Search 179/1 E, 1 F, 1 GA; teriorshape of a pyramid is mounted within the cabi- 181/179, 133, 175, 182,155, 31 B; 325/310, net, with the pyramid base disposed toward the rear352 wall and the pyramid vertex disposed toward the front speakeropening. A speaker is mounted in the housing [56] References Cited todirect sound through the pyramid base. A sound re- UNITED STATES PATENTSflector having the shape of a pyramid is mounted at 2,373,692 4/1945Klipsch 181/152 base. on the rear wall the reflector i 2 516 2/1959 Hbeing directed toward the speaker. Sound emitted offman 179/1 E 1 fromthe speaker 15 reflected from the reflector and FOREIGN PATENTS ORAPPLICATIONS travels between the housing and the interior walls of916,842 12/1946 France 181/27 the cabinet'outwardly through the frontspeaker open- 252,053 5/1925 United Kingdom 181/27 ing to provide a flatimpedance curve and a smooth base response -to to approximately 2,000cycles per second.

l7,Claims, 5 Drawing Figures FOLDED BASS HORN SPEAKER FIELD OF THEINVENTION This invention relates to speakers, and more particularlyrelates to'folded bass horn speakers.

THE PRIOR: ART

Large bass horn speakers are commonly used for projection of bass soundat outdoor concerts and the like. Such bass speakers generally comprisea cone speaker having 'a large horn attached to the front thereof andhaving a small rear chamber which encloses the back of the speaker.However, the size of such bass speakers is a distinct drawback, as suchspeakers may often be more than 6 feet wide, 4.feet tall and'8 feetdeep. A need has thus arisen for a bass speaker which approaches theefficiency of prior large bass horn speakers, and yet which isrelatively small and compact.

It'has been heretofore known to provide a folded horn speaker wherein aspeaker is oriented toward the rear of a cabinet such that the sound isdirected outwardly from the periphery of the speaker through the frontof the cabinet. An example of such a prior folded horn speaker utilizeda W enclosure, wherein the rear baffle or reflector was provided withthe general shape of the letter W in order to reflect the sound out thefront of thecabinet. However, such previously developed folded hornspeakers have not provided the desired flat'impedance curve to provide ahigh efficiency enclosure, nor have such prior speakers provided asmooth bass response up to approximately 2000 cycles per second. I

SUMMARY OF THE INVENTION The present invention provides a folded basshorn speaker which eliminates the size problems heretofore associatedwith prior large bass horn speakers and which provides an extremely flatimpedance curve and a smooth bass response up to 2000 cycles per second.

In accordance with the invention, the present speaker includes a cabinethaving a rear wall and a front speaker opening. A housing having theshape of a pyramid is. mounted within the cabinet, the base of thepyramid being open and disposed toward the rear wall and the vertex ofthe pyramid being disposed toward the front speaker opening. A speakeris mounted within the housing to direct sound out from the open base ofthe pyramid. A sound reflector extends from the rear wall toward thespeaker, such that sound emitted from the speaker is reflected from thereflector and travels around the periphery of the housing and out thefront speaker opening of the cabinet.

In accordance with another aspect of the invention, a folded hornspeaker includes a rectangular cabinet having a rear wall and a frontspeaker opening. A housof the housing outwardly through thefront speakeropening.

In accordance with a more specific aspect of the invention, a foldedbass horn speaker includes a speaker cabinet having a rear wall and afront speaker opening. A housing having an exterior shape of a pyramidis mounted within the cabinet, with the pyramid base disposed toward therear wall and the pyramid vertex disposed toward the front speakeropening. A speaker is mounted within the housing to direct sound throughthe pyramid base. A sound reflector having the configuration of apyramid is mounted with the base of the pyramid on the rear wall and thereflector pyramid vertex being directed toward the speaker. Sound isemitted from the speaker and reflected from the reflector and travelsbetween the housing and the interior walls of the cabinet outwardlythrough the front speaker open- DESCRIPTION OF THE DRAWINGS For a moredetailed description of the present invention and for further objectsand advantages thereof, reference may now be made to the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view taken from the front of the present foldedbass speaker;

FIG. 2 is a sectional view taken through the center of the speaker shownin FIG. 1;

FIG. 3 is a front view of the speaker shown in FIG.

FIG. 4 is a sectional view of a second embodiment of the presentspeaker; and

FIG. Sis a sectional view of a third embodiment of the present speaker.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a perspectiveview of the preferred embodiment of the present folded bass horn speakeridentified generally by numeral 10. Speaker 10 comprises a rectangularcabinet 12 having a rear wall 14 and a front speaker opening 16. In thepreferred embodiment, the front speaker opening 16 is open asillustrated. However, if desired, a fabric cover 19 may be disposed overthe front speaker'opening.

A housing 18 which has the slope of a pyramid is disposed within thecabinet 12. The base of the pyramid 18 is open, as shown in FIG. 2, andis disposed toward the rear wall 14. The vertex 20 of the housing 18 isdisposed toward the front speaker opening 16. Braces 22 are connected atthe four corners of the pyramid housing 18 and are connected by bolts orthe like to the interior walls of the cabinet 12, as shown in FIG. 3.

Referring to FIG. 2, a conventional bass speaker 24 is mounted withinthe housing 18 by connecting the outer periphery of the speaker cone 26to an inwardly directed edge 28 of the housing. The speaker 24 includesa conventional driver unit 30 which generates acoustic energy in thewell known manner.

' A sound reflector 32 is also provided with the shape of a pyramid,with the pyramid base being rigidly attached to the rear wall 14 andwith the pyramid vertex being disposed toward speaker 24. The pyramidvertex of reflector32 is disposed within the speaker cone 26, but thereflector 32 is spaced apart from the speaker cone 26. The distancebetween the surface of the reflector 32 and the speaker cone 26increases gradually toward the periphery of the speaker 24. Curvedsurfaces 34 are rigidly connected along the intersections of the rearwall 14 and the interior side walls of the cabinet 12. The curvedsurfaces 34 are thus disposed between the base of the reflector 32 andthe interior walls of the cabinet 12 in order to provide a smooth travelpath for sound generated from speaker 24.

In operation of the speaker 10, sound is emitted from the speaker 24 andis reflected from the reflector 32 and travels outwardly around theperiphery of the speaker cone 26. The sound is then reflected upwardlyby the curved surfaces 34 and out the front speaker opening 16. Thepresent speaker thus fold the bass horn in four directions along theinterior sides of the cabinet 12. The distance between the housing 18and the interior walls of the cabinet 12 increases as the sound movestoward the front speaker opening 16. The speaker thus serves as animpedance matching transformer which couples the heavy diaphram of thedriver unit 30 to the air mass at the front speaker opening 16 of thecabinet 12. The present speaker provides an extremely flat impedancecurve to provide a very high efficiency speaker enclosure. The speakerdoes not cancel out mid bass frequencies and has a smooth frequencyresponse up to 2000 cycles per second.

An important aspect of the present invention is that the housing 18 isprovided with the mathematical dimensions of the Great Pyramid in Egypt.The formula for determining the height and apothem of the pyramid shapeof the housing 18 is thus as follows:

Base multiplied by 4 divided by pi (3.1416) height Base divided by 2multiplied by 1.618 apothem When utilizing an 18 inch speaker, the basedimension of the pyramidal shape of housing 18 is thus exactly oneEgyptian Cubit which is slightly over 20-% inches. The angle of thesides of the pyramidal shaped housing 18 is exactly 51.51 degrees. Whena 15 inch speaker is utilized, the pyramid base dimension of the pyramidhousing 18 is 17 inches. For a 12 inch speaker, the pyramid basedimension is 15 inches and for a 4 inch speaker the base dimension ofthe pyramid housing is 6 inches. Various size cabinets will of course beutilized for the present speaker depending upon the size speakerrequired, but speaker cabinets having a depth of 18 to inches and inchesby 30 inches square accommodate an 18 inch speaker. Cabinets for smallerspeakers will be proportionally smaller.

The pyramidal shape of the reflector 32 is not related to pi, but has abase width equal to approximately the diameter of the speaker and hasside walls extending at 30 to the base. In the preferred embodiment, thesound reflector 32 and the curved surfaces 34 are constructed frommolded fiberglass.

FlG. 4 illustrates a sectional view of a second embodiment of theinvention wherein like numerals are utilized for like and correspondingparts previously shown. The structure of FIG. 4 is generally similar tothat previously disclosed, with the exception of rectangular side walls40 which are disposed between the pyramid housing 18 and the braces 22.The rectangular side walls 40 are parallel to the side walls of thecabinet 12 and serve to lengthen the distance between the speaker 24 andthe housing 18. The longer the side walls 40, the more the base responseof the speaker is increased. The side walls of the cabinet 12 arerequired to be sufficiently deep in order to accommodate the increasedheight of the housing 18. For the embodiment shown in FIG. 4, thecabinet walls may range from 17 inches to 25 inches deep.

FIG. 5 illustrates a third embodiment of the invention which is similarto the embodiment shown in FIG. 4, with the exception that four sidewalls 50 are disposed between the edges of the pyramid housing 18 andthe braces 22. The side walls 50 are inclined relative to the interiorside walls of the cabinet 12 to provide a path for the sound emanatingfrom the speaker 24 which gradually increases in size as the soundpasses from the reflector 32 upwardly along the interior sides of thecabinet 12.

It may thus be seen that the present invention provides an improved bassspeaker which is substantially smaller than previously used bassspeakers, yet which provides anextremely flat impedance curve for a highefficiency enclosure and which has a smooth bass response up toapproximately 2000 cycles per second. The present speaker accomplishesthis performance in a small package with the utilization of a pyramidalshaped speaker housing and reflector oriented relative to another in themanner described in order to essentially fold the speaker horn in fourdirections to adapt the circular speaker to a square cabinet.

Whereas the present invention has been described with respect tospecific embodiments thereof, it will be understood that various changesand modifications will be suggested to one skilled in the art, and it isintended to encompass such changes and modifications as fall within thescope of the appended claims.

What is claimed is:

1. A folded horn speaker comprising:

a rectangular cabinet having a rear wall and a front speaker opening,

a housing having a closed end directed toward said front speaker openingand an open end directed toward said rear wall,

a speaker mounted within said housing for directing acoustic energythrough said open end toward said rear wall,

a four sided reflector having the shape of a pyramid with therectangular pyramid base attached to said rear wall and the pyramidvertex disposed toward said speaker, said reflector being spaced fromsaid speaker such that acoustic energy is reflected from said reflectorand travels around the periphery of said housing outwardly through saidfront speaker opening.

2. The folded horn speaker of claim 1 wherein the edges of saidreflector pyramid are parallel to the sides of said rectangular cabinet.

3. The folded horn speaker of claim 1 wherein said housing is shaped asa pyramid.

4. The folded horn speaker of claim 1 wherein the sides of saidreflector pyramid extend from the pyramid base at an angle of 30.

5. The folded horn speaker of claim 1 and further comprising:

curved walls disposed between the base of said reflector pyramid and theside walls of said cabinet in order to direct sound outwardly throughsaid front speaker opening.

6. The folded horn speaker of claim 1 and further comprising:

braces extending from said housing and connected at the ends thereof tothe corners of said cabinet.

7. The folded horn speaker of claim 1 wherein the vertex of said pyramidreflector extends into the cone of said speaker.

8. A folded bass horn speaker comprising:

a speaker cabinet having a rear wall and a front speaker opening,

a four sided housing having the exterior shape of a pyramid mountedwithin said cabinet with the rectangular pyramid base disposed towardsaid rear wall and the pyramid vertex disposed toward said front speakeropening,

a speaker mounted within said housing to direct sound through saidpyramid base,

a four sided sound reflector having the configuration of a pyramid, therectangular base of said reflector mounted on said rear wall and thereflector vertex being directed toward said speaker,

wherein sound emitted from said speaker is reflected from said reflectorand travels between the periphery of said housing and the interior wallsof said cabinet outwardly through said front speaker openmg.

9. The folded bass horn speaker of claim 8 wherein said cabinet isrectangular and wherein the base edges of said housing and saidreflector are parallel to the side walls of said cabinet.

10. The folded bass horn speaker of claim 8 wherein the vertex of saidreflector extends within the speaker cone of said speaker.

11. The folded bass horn speaker of claim 8 and further comprising:

planar side walls extending from the base of said four sided housingtoward said rear wall.

12. The folded bass horn speaker of claim 1 1 wherein said side wallsare parallel to the interior walls of said cabinet.

13. The folded bass horn speaker of claim 11 wherein said side walls areslanted relative to the interior walls of said cabinet.

14. The folded bass horn speaker of claim 8 wherein the distance betweensaid reflector and said speaker increases toward the periphery of saidspeaker.

15. The folded bass horn speaker of claim 8 wherein the height of saidhousing pyramid is equal to the housing pyramid base multiplied by fourand divided by pi.

16. The folded bass horn speaker of claim 8 wherein the walls of saidhousing pyramid are oriented at 5 1.5 1 to the housing pyramid base.

17. The folded bass horn speaker of claim 8 wherein the horn speaker hasa substantially flat impedance curve and a smooth bass frequencyresponse up to approximately 2000 cycles per second.

1. A folded horn speaker comprising: a rectangular cabinet having a rearwall and a front speaker opening, a housing having a closed end directedtoward said front speaker opening and an open end directed toward saidrear wall, a speaker mounted within said housing for directing acousticenergy through said open end toward said rear wall, a four sidedreflector having the shape of a pyramid with the rectangular pyramidbase attached to said rear wall and the pyramid vertex disposed towardsaid speaker, said reflector being spaced from said speaker such thatacoustic energy is reflected from said reflector and travels around theperiphery of said housing outwardly through said front speaker opening.2. The folded horn speaker of claim 1 wherein the edges of saidreflector pyramid are parallel to the sides of said rectangular cabinet.3. The folded horn speaker of claim 1 wherein said housing is shaped asa pyramid.
 4. The folded horn speaker of claim 1 wherein the sides ofsaid reflector pyramid extend from the pyramid base at an angle of 30*.5. The folded horn speaker of claim 1 and further comprising: curvedwalls disposed between the base of said reflector pyramid and the sidewalls of said cabinet in order to direct sound outwardly through saidfront speaker opening.
 6. The folded horn speaker of claim 1 and furthercomprising: braces extending from said housing and connected at the endsthereof to the corners of said cabinet.
 7. The folded horn speaker ofclaim 1 wherein the vertex of said pyramid reflector extends into thecone of said speaker.
 8. A folded bass horn speaker comprising: aspeaker cabinet having a rear wall and a front speaker opening, a foursided housing having the exterior shape of a pyramid mounted within saidcabinet with the rectangular pyramid base disposed toward said rear walland the pyramid vertex disposed toward said front speaker opening, aspeaker mounted within said housing to direct sound through said pyramidbase, a four sided sound reflector having the configuration of apyramid, the rectangular base of said reflector mounted on said rearwall and the reflector vertex being directed toward said speaker,wherein sound emitted from said speaker is reflected from said reflectorand travels between the periphery of said housing and the interior wallsof said cabinet outwardly through said front speaker opening.
 9. Thefolded bass horn speaker of claim 8 wherein said cabinet is rectangularand wherein the base edges of said housing and said reflector areparallel to the side walls of said cabinet.
 10. The folded bass hornspeaker of claim 8 wherein the vertex of said reflector extends withinthe speaker cone of said speaker.
 11. The folded bass horn speaker ofclaim 8 and further comprising: planar side walls extending from thebase of said four sided housing toward said rear wall.
 12. The foldedbass horn speaker of claim 11 wheRein said side walls are parallel tothe interior walls of said cabinet.
 13. The folded bass horn speaker ofclaim 11 wherein said side walls are slanted relative to the interiorwalls of said cabinet.
 14. The folded bass horn speaker of claim 8wherein the distance between said reflector and said speaker increasestoward the periphery of said speaker.
 15. The folded bass horn speakerof claim 8 wherein the height of said housing pyramid is equal to thehousing pyramid base multiplied by four and divided by pi.
 16. Thefolded bass horn speaker of claim 8 wherein the walls of said housingpyramid are oriented at 51.51* to the housing pyramid base.
 17. Thefolded bass horn speaker of claim 8 wherein the horn speaker has asubstantially flat impedance curve and a smooth bass frequency responseup to approximately 2000 cycles per second.